Condensed Consolidated Statements of Cash Flows - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2019	Dec. 31, 2018	Dec. 31, 2017
Cash provided from (used for) operating activities:
Net income	$ 760,790	$ 701,466	$ 1,454,494
Adjustments to reconcile net income from continuing operations to cash provided from continuing operations:
Loss (income) from discontinued operations, net of income taxes	92	44	3,769
Increase (decrease) in future policy benefits	661,567	664,997	687,407
Increase (decrease) in other policy benefits	15,900	17,134	31,784
Deferral of policy acquisition costs	(753,661)	(699,551)	(660,134)
Amortization of deferred policy acquisition costs	551,726	516,690	490,403
Change in current and deferred income taxes	68,588	69,369	(700,660)
Realized (gains) losses	(20,621)	1,804	(23,611)
Other, net	62,194	4,463	67,933
Net cash provided from (used for) continuing operations	1,346,575	1,276,416	1,351,385
Net cash provided from (used for) discontinued operations	17,299	1,231	77,673
Cash provided from (used for) operating activities	1,363,874	1,277,647	1,429,058
Cash provided from (used for) investing activities:
Fixed maturities available for sale—sold	79,108	32,021	67,246
Fixed maturities available for sale—matured or other redemptions	840,222	343,712	488,843
Other long-term investments	5,134	477	3,534
Total investments sold or matured	924,464	376,210	559,623
Acquisition of investments:
Fixed maturities—available for sale	(1,552,956)	(1,155,539)	(1,314,609)
Other long-term investments	(123,332)	(93,631)	(55,096)
Total investments acquired	(1,676,288)	(1,249,170)	(1,369,705)
Net (increase) decrease in policy loans	(25,426)	(20,537)	(21,554)
Net (increase) decrease in short-term investments	34,003	63,783	(55,031)
Additions to properties	(42,203)	(45,092)	(20,285)
Sale of other assets	32	1,987	18
Investments in low-income housing interests	(23,893)	(23,404)	(19,890)
Net Cash Provided by (Used in) Investing Activities, Total	(809,311)	(896,223)	(926,824)
Cash provided from (used for) financing activities:
Issuance of common stock	83,163	36,091	61,215
Cash dividends paid to shareholders	(74,188)	(71,421)	(68,831)
Repayment of debt	(6,875)	(327,762)	(126,875)
Proceeds from issuance of debt	0	550,000	125,000
Payment for debt issuance costs	0	(6,969)	(1,661)
Net borrowing (repayment) of commercial paper	(11,610)	(22,719)	61,092
Acquisition of treasury stock	(459,569)	(421,749)	(412,989)
Net receipts (payments) from deposit-type products	(121,429)	(126,991)	(90,932)
Cash provided from (used for) financing activities	(590,508)	(391,520)	(453,981)
Effect of foreign exchange rate changes on cash	(9,148)	12,559	(5,853)
Net increase (decrease) in cash	(45,093)	2,463	42,400
Cash at beginning of year	121,026	118,563	76,163
Cash at end of year	$ 75,933	$ 121,026	$ 118,563